Metal converting furnace apparatus

ABSTRACT

The combination of a metal converting furnace and a pair of diametrically opposed support assemblies mounted thereon is disclosed. Each of the support assemblies includes brackets mounted directly on the outer surface of the furnace and arranged to define a central pocket and slots extending radially outwardly from the pocket. A shaft has a hub formed on the inner end thereof and is shaped and sized to fit within the pocket, and lugs extending radially outwardly from the hub and shaped and sized to be received in the slots. The slots and lugs are shaped and sized to permit a reasonable amount of misalignment therebetween whereby mating of the shaft to the brackets is in the nature of a flexible connection. A heat shield is mounted on the outer surface of the furnace with the shield surrounding the tap spout of the furnace and enclosing an area around the spout. The shield serves as a heat sink for the heat radiated from molten metal poured into a ladle. Finally, the metal shell of the furnace is thickened in the area surrounding the tap spout. The thickened wall serves to resist distortion due to the thermal expansion concentrated in the area of the wall where the molten metal flows during tap off.

United States Patent Mevissen 154] METAL CONVERTING FURNACE APPARATUS[72] Inventor: Ernst A. Mevissen, Robinson Township, Allegheny County,Pa.

[73] Assignee: Dravo Corporation, Pittsburgh, Pa.

[22] Filed: Aug, 20, 1970 [21] Appl. No: 65,651

Primary Examiner-Gerald A. Dost Attorney-Parmelee, Utzler & Welsh [5 7ABSTRACT The combination of a metal converting furnace and a [451 Oct.3, 1972 pair of diametrically opposed support assemblies mounted thereonis disclosed. Each of the support assemblies includes brackets mounteddirectly on the outer surface of the furnace and arranged to define acentral pocket and slots extending radially outwardly from the pocket. Ashaft has a hub formed on the inner end thereof and is shaped and sizedto fit within the pocket, and lugs extending radially outwardly from thehub and shaped and sized to be received in the slots. The slots and lugsare shaped and sized to permit a reasonable amount of misalignmenttherebetween whereby mating of the shaft to the brackets is in thenature of a flexible connection. A heat shield is mounted on the outersurface of "the furnace with the shield surrounding the tap spout of thefurnace and enclosing an area around the spout. The shield serves as aheat sink for the heat radiated from molten metal poured into a ladle.Finally, the metal shell of the furnace is thickened in the areasurrounding the tap spout. The thickened wall serves to resistdistortion due to the thermal expansion concentrated in the area 25Claims, 8 Drawing Figures METAL CONVERTING FURNACE APPARATUS Thisinvention relates to metal converting furnace apparatus, and moreparticularly to the combination of a metal converting furnace andsupport assemblies therefor.

BOF and other converting furnaces used in refining metal havecustomarily used a trunnion ring fixed around a central portion of thefurnace, with opposed trunnion shafts fixed to the ring. The trunnionshafts are usually supported for rotation, with one of the shafts beingcoupled with a drive motor through reduction gearing, thus enabling thefurnace to be tilted for molten metal or slag tap off. Convertingfurnaces of this type generate tremendous quantities of heat atextremely high temperatures during refining operations. The hightemperatures cause the metal shell of the furnace to expand resulting indistortion of the shell and high local stresses. Because of theexpansion of the shell, the trunnion ring is also subject to expansionand resulting permanent distortion. Accordingly, the shell and trunnionring must be periodically repaired and sometimes replaced. The trunnionring is also subject to physical abuse, as for example during shipment,which causes distortion, necessitating repair. Also, the ring by itsvery nature, is very costly to fabricate and the expense is compoundedsince the ring requires elaborate attachment arrangements with thefurnace vessel which must be designed to accommodate the radial andaxial expansion of the vessel. Additionally, tedious and time consumingfield fitting and aligning of the trunnion ring to the support structureon the furnace is necessary.

Another undesireable feature of a trunnion ring support arrangement isthe fact that the ring is very heavy and, thus, prevents, for allpractical purposes, added weight to the furnace. For example, distortionof the metal shell of the furnace may be minimized by increasing thethickness of the metal wall or by adding radiation heat shields to thefurnace. Doing this, however, would necessitate a larger, and thereforeheavier, trunnion ring as well as an increase in the size of thetrunnion shafts and bearings therefor, and usually an increase in thecapacity of the drive motors and gear train used to tilt the furnace.Because these increases are very expensive, design of the furnace toavoid distortion may be compromised with resulting unnecessarydistortion of the furnace shell. 7

Various attempts have been made to avoid damage to the trunnion ring dueto the thermal expansion between the furnace and the ring. Means havebeen provided between the furnace and the trunnion ring to allow thefurnace to expand independently of the ring. That is, the furnace isallowed to expand without transmitting that expansion directly to thetrunnion ring. Such means usually involve complicated and costly slidingbrackets and guides, requiring careful selection of clearances which areoften upset due to the physical abuse given to the trunnion ring, makingalignment a cumbersome procedure. The sliding brackets and guidearrangements are also subject to damage from thermal expansion of thefurnace when the clearances are improperly selected or are changedbecause of physical abuse.

Direct mounting of the trunnion shafts to the furnace has been suggestedfor overcoming the trunnion ring problems. Such direct mounting,however, has its problems also, especially with high local stressesaround the mounting structure on the furnace created by the thermalexpansion of the metal shell. In addition there is the problem ofaligning the shafts to the shaft support structure on the furnace. Thisalignment problem exists when new shafts are mounted to new furnaces,but becomes considerably greater when a used shaft must be remounted toa used furnace. The high local stresses to the support structure on thefurnace will frequently result in distortion of the various elementsforming the structure. Thus, alignment of the shafts to the supportstructure becomes virtually impossible without major reworking orreplacement of the distorted elements. If a new vessel replaces an oldone, most likely new trunnion shafts will also be provided.

l overcome those problems stated above by providing a supportarrangement for metal converting furnaces which does not use a trunnionring. My support arrangement is direct furnace mounted, but avoids thedirect mounting alignment and local stress distortion problems. Moreparticularly, I provide a combination of a metal converting furnace anda pair of opposed support assemblies, with each assembly preferablycomprising: ground supported shaft means coupled to the furnace forsupporting the furnace above ground level; and flexible connection meanson the shaft and furnace, respectively, engaging each other forsupporting the furnace on the shaft. Since the connections between theshafts andfurnace are flexible connections, a certain degree ofmisalignment caused, for example, by distortion of parts resulting fromthermal expansion or fabrication error is allowed. Also, the flexibleconnection will allow the connection structure on the furnace to movewith the furnace during thermal expansion, and independently of themating connection on the trunnion shaft. Because the support structuresmove relative to each other the high local stresses otherwise resultingin the support structures of rigidly furnace mounted trunnion shafts arevirtually eliminated. In my preferred form I achieve these results byproviding a spline type of a connection which I illustrate as includingfour brackets fixed to the metal shell of the furnace and arranged todefine four slots spaced ninety degrees apart and extending radiallyfrom a central pocket. The inner end portion of each of my trunnionshafts has a hub which is shaped and sized to fit in the pocket, andalso has four lugs extending radially from the hub; The lugs are fittedinto the slots, with the shape and size of the slots and lugs beingselected to permit a certain degree of misalignment therebetween typicalof any spline-type flexible coupling. Thus, misalignment is compensatedfor. Local stresses from heat expansion will also be eliminated sincethe brackets on the furnace wall will move with the furnace to open theslots. My invention contemplates either a fixed orientation furnace orone that is tiltable. With a tiltable arrangement a drive motor would becoupled to one of the trunnion shafts through suitable reductiongearing. In both the tiltable and stationary furnace arrangements, oneof the shafts would be supported for limited axial movement so that theexpansion of the furnace will be taken up by that shaft.

By eliminating the heavy trunnion ring, the furnace may be made largerand heavier without any necessity of changing the size of the trunnionshafts, and bearings supports, and drives therefor. Thus, my inventionpermits addition of weight to the critical points of the furnace for thepurpose, for example, of resisting distortion resulting from thermalexpansion. One area of a tiltable furnace subject to the greatestdistortion from thermal expansion is that area of the metal shell arounda molten metal tap. When the metal is being tapped off it will beconcentrated on the inner wall of the furnace surrounding the tap andthe metal shell will tend to creep and enlarge in time, more so than therest of the shell, and to become, as is said in the trade, pregnant. Thedistorted portion of the shell is either replaced or, if the distortionis too great, the entire furnace is scrapped. The external area of thefurnace around the tap is also subjected to radiant heat from the moltenmetal as it is being poured into a ladle. The radiant heat further addsto the distortion of the metal shell around the tap. I considerablyreduce the distortion problems just mentioned by providing, in oneinstance, a thickened metal shell in the area of the furnace around thetap, and, in a second instance, providing a heat shield mounted on theouter wall of the metal shell and covering the area around the tap whichwould be subject to the radiation from a ladle into which molten metalwas being poured. The thickened shell will resist distortion resultingfrom the concentrated volume of metal thereon, while the heat shieldwill prevent distortion by serving as a heat sink between the shell andthe ladle of molten metal. The heat shield would be subject todistortion but it could be easily and more cheaply replaced as comparedto replacing a section of metal shell.

Other details and advantages of this invention will become apparent asthe following descriptions of certain present preferred embodimentsthereof proceed.

In the accompanying drawings I have shown certain present preferredembodiments of this invention in which:

FIG. 1 is a side elevation view partly in section of a combination metalconverting furnace and support assemblies therefor, embodying one formof the present invention;

FIG. 2 is a view looking along the line IIlI of FIG. 1 with certainportions of the furnace being cut away and heat shield around one of thetap spouts being in section, to show details of construction;

FIG. 3 is a top plan view of the furnace and supports of FIG. 1 andincluding drive motors and primary gear reduction boxes coupled with oneof the trunnion shafts;

FIG. 4 is an enlarged elevation view, partly in section, of the trunnionshaft and support members Referring now to the drawings, and especiallyto FIGS. 1-6, there is shown a typical open-mouthed metal convertingfurnace 10 as would be used in the basic oxygen refining of steel. Thefurnace 10 has an outer metal shell 11 and a refractory block innershell 12. The furnace 10 is shown in its upright metal charging orrefining position; that is, with its longitudinal centerline beingvertical, and location of elements hereinafter will be described inreference to the upright position. The furnace 10 is a tiltable one,being supported above ground level for rotation about a generallyhorizontal axis by a pair of diametrically opposed support assemblies14, and 16, respectively. Identical molten metal tap spouts 18 and 20are arranged on opposite sides of the furnace at upper portions thereof,thereby allowing the furnace to be tilted in two directions for metaltap-off.

Both support assemblies 14 and 16 are arranged for direct connectionwith the outer wall of the furnace. That is, the support assemblies 14and 16 are not coupled to a trunnion ring mounted on the furnace.Support assembly 14 is coupled to power means for supplying the drivingforce needed to tilt the furnace. Support assembly 14 includes anelongated trunnion shaft member 21 having a generally frusto-conicalshape, and is supported for rotation with its axis horizontally orientedby spaced bearings 22 and 24, both of which are arranged in housing 26resting on and anchored to a reinforced concrete foundation 28. Theright end, as viewed in FIG. 1, of trunnion shaft 21 is connected to thefurnace in a manner to be described hereinafter. Since it is the sameessential coupling arrangement as is used with the other supportassembly 16 only one description for both will be made in the interestof avoiding redundant description. Trunnion shaft 21 of support assembly14 is driven by power means 30 and 32, shown in FIG. 3, arranged forselectively driving the shaft in reverse directions. Each power means 30and 32 includes a pair of motors 34 and 36 connected with a source ofelectrical power, not shown, both of which motors are coupled to aprimary reduction gear arranged in housings 38. The primary reductiongear is coupled with a drive shaft 40 which is supported in housing 26as shown in FIG. 1, which drive shaft 40 has a pinion gear 42 mounted onan intermediate portion thereof. The pinion gear 42 engages a secondreduction gear 44 arranged on an intermediate portion of trunnion shaft21.

Support assembly 16 includes an elongated trunnion shaft 50 of generallyfrusto-conical shape having its longitudinal axis coaxial with the axisof trunnion shaft 21, and supported for rotation by bearings 52 and 54arranged on a bearing stand 56 which rests on and is anchored to areinforced concrete foundation 58. A cover 59 is placed over thebearings 52 and 54 to protect them from damage. Trunnion shaft 50 servesas an idler shaft and is arranged to move a fixed distance along itshorizontal axis so that axial thermal expansion of the furnace 10 willbe taken up by shaft 50.

The right end of trunnion shaft 21 and left end of trunnion shaft 50 asviewed in FIG. 1, are both identically connected to the furnace. Asstated earlier, one description of both connections will be made withthe understanding that it refers to both support assemblies 14 and 16.Referring now to the connection arrangement for support assembly 16,there is provided four identically shaped brackets 60 fixed to the outerwall of the metal shell 11 of furnace 10. Each bracket 60 is suitablycurved to conform with the curvature of furnace and is joined to asupporting pin 61, shown in FIG. 5, and fixed to the metal shell 11 by aseries of fasteners such as bolts, for example. Each bracket 60 isappropriately shaped and sized in the manner shown clearly in FIG. 4, sothat when the four brackets are fixed to the metal shell 11 as shown,they define with portions of metal shell 11 a central pocket 62 withfour slots 63, 64, 65, 66 extending radially from the pocket and havingtheir centerline spaced generally 90 apart. Slots 63 and 65 areidentically shaped and are located at the 12 and 6 oclock positionsrespectively; while slots 64 and 66 are identical and are located at 3and oclock respectively. However, the shape of all the slots 63, 64, 65,66 adjacent to pocket 62 is the same for all, for reasons which willbecome apparent as the description continues.

The left or inner end portion 70 of trunnion shaft 50 is formed toinclude a hub portion 72 shaped to fit within pocket 62 defined bybrackets 60. Four identically shaped lugs 74 extend radially outwardlyfrom hub portion 72 and have their centerlines spaced generally ninetydegrees apart. Each lug 74 is shaped and sized to fit within theidentically shaped portions of the slots 63, 64, 65, 66 defined bybrackets 60. Hardened steel wear plates 78 are arranged between the sidefaces of lugs 74 and the wall of the slots 63, 64, 65, 66. The wearplates 78 are sized to permit a slidable fit between the lugs and theslots. As shown in FIGS. 5 and 6, a clearance exists between the face orleft end portion 70 of shaft 50 and the furnace. Limited axial movementof the shaft 50 toward and away from the furnace is thus permitted butis restricted by four identical retention brackets 80, one each of whichis mounted, as with removable bolts for example, to the metal shell 11of the furnace 10 in each of the slots 63, 64, 65, 66 defined bybrackets 60. Each retention bracket 80 has parallel tabs 81 and 82,shown clearly in FIG. 6, which serve as stops for lugs 74 to limit theaxial movement of trunnion shaft 50. A clearance is also providedbetween the free ends of lugs 74 and the inner face 84 formed betweenthe tabs 81 and 82 of the retention brackets 80. By virtue of theclearances just described, the shaft 50 has a certain degree of movementrelative to the brackets 60. Thus, the connection of the shaft 50 at theinner end portion 70 thereof to the brackets 60 is in the nature of aflexible splined connection-the lugs 74 being external splines and theslots 63, 64, 65, 66 being internal splines defined by the four brackets60. The clearances between the lugs 74 and the surfaces of the slots asdefined by brackets 60 and retention brackets 80 allows a reasonabledegree of misalignment therebetween thus permitting the trunnion shaft50 to be flexibly connected to brackets 60 (i.e., connected to furnace10).

Brackets 60 will move and expand with the metal shell 11 of furnace 10when it thermally expands during refining of metal. As the metal shell11 expands circumferentially so will the brackets 60 to thereby widenthe slots 63, 64, 65, 66. By virtue of this widening of the slots, localstresses are prevented between the brackets 60 and the inner end portion70 of shaft 50. The

loosening of the slots can be controlled to avoid any adverseconsequences, by making a tight fit between the sides of lugs 74 andslots. Proper sizing of the wear plates 78 will provide the desiredtight fit. In any event the opening of the clearances between the lugsand slots will be very small, as compared with a trunnion ring bracketarrangement, since the dimensions of the slots are small compared to thetrunnion ring bracket axial spacing. Stress on the trunnion shafts 21and 50 due to radial expansion of the vessel is avoided since trunnionshaft 50 is supported to move a limited amount along its horizontalaxis, thus allowing the radial expansion of the vessel 10 to be taken upby the shaft 50. Another advantage of the flexible connectionarrangement, is that a very small force is transmitted to the vessel, ascompared with the force which would be transmitted to the vessel byrigidly connected shaft ar-.

rangements. in a rigidly connected shaft arrangement, the moment armacting on the vessel would be the length of the shaft. In the presentinvention-the trunnion shafts will not act directly on the vessel wallsince they are flexibly connected with the vessel. The only moment armsacting on the vessel in this invention are the brackets, which areconsiderably shorter in length than rigidly connected trunnion shafts.The large moment arm of the rigid connection could possibly damage thevessel wall. Thus, I diminish this possibility by decreasing the momentarms to a very small value.

When the furnace 10 is in the charge or refining position shown in thedrawings, the 3 and 9 oclock lugs 74 carry the load while the 12 and 6oclock lugs are under no-load but do serve to stabilize the furnace.When the furnace is tilted the load on the lugs will shift. it should benoted at this juncture that the orientation of the centerlines of thelugs and slots as described and illustrated is not critical and may bearranged as desired with reference to the longitudinal centerline of thefurnace. For example, as compared with the previously describedstructure, all of the lugs 74 could be shifted 45 out of phase and thebrackets 60 arranged accordingly to define slots 45 out of phase. Anyother shifting could be selected as desired. Also it is' noted that fourexternal splines (lugs 74) and internal splines (slots) are notcritical, and any number may be selected as desired. Four splines is apractical number, but anywhere from two and up to a practical number maybe used. Moreover, my flexible connection between the trunnion shaftsand the vessel need not be aspline arrangement but may take on any otherform which those skilled in the art would readily recognize.

FlGS.7 and 8 illustrate another flexible connection arrangement betweenthe trunnion shafts and the furnace in accordance with the presentinvention. In this arrangement the splines are reversed, the externalsplines being formed on brackets mounted on the furnace and the internalsplines being formed on the trunnion shaft. As shown, inner end portionof trunnion shaft 50' which is supported for rotation in the samegeneral manner as trunnion shaft 50, has four identical slots 92 formedtherein and spaced with their centerlines being ninety degrees apart.Four identically shaped brackets 96 are secured to the metal shell of afurnace, each bracket having a lug 97 depending from a main body portionand received in a slot 92 of sleeve member 90. Hardened steel wearplates are arranged between the side face of the lugs 97 and theopposite faces of the slots 92. A clearance exists between the face ofinner portion 90 of shaft 50 and the opposite wall portion of thefurnace. Some axial movement by the trunnion shaft 50' toward and awayfrom the furnace is thus provided and the extent of such movement islimited by trunnion retention brackets 98 fixed to the furnace andarranged to fit loosely over the inner end portion 90. A clearance isalso provided between the radial outer end of each lug 97 and the end ofthe slot 92 facing the lug. The clearances mentioned in this paragraphthus provide the necessary freedom of movement to provide reasonabledegree of misalignment between the lugs 97 and slots 92, much in thesame manner as the embodiment of FIGS. 1-6.

The brackets 96 of the embodiment of FIGS. 7 and 8 will tend to expandwith the metal shell of the furnace during metal refining. Duringcircumferential expansion the mating between the lugs 97 and slots 92will become tighter, whereas in the first embodiment the mating betweenthe lugs and slots became looser. Nevertheless, the coupling arrangementbetween trunnion shaft 50' and the furnace will be devoid of localstresses caused by thermal expansion. Any damaging stress between thelugs 97 and trunnion shaft 50' may be simply avoided by proper sizeselections of wear plates 95 for giving a suitable clearance between theside faces of the lugs 97 and the opposite faces of the slots 92, whichclearance will allow for the expansion of the lugs 97 without causingdistortion of the sleeve 90. In any event, whatever stresses are createdbetween the lugs 97 and the shaft 50' will be very low since the degreeof expansion of the lugs will be small because of their small sizes(i.e., as compared to a trunnion ring and bracket arrangement, forexample).

Referring again to the first embodiment of this invention, there isprovided, as shown in FIGS. 1-3, slag shields 100 and 102 suitably fixedto the furnace and covering the flexible connections (i.e., brackets 60and inner end portion 70 of trunnion shaft 50) to protect them frommolten metal and slag spatter. The slag shields 100 and 102 are opened,as shown, so that the vessel may be easily accessible for inspection orservice.

As mentioned earlier in the introductory portion of this description,the area of the furnace 10 subject to the greatest distortion due tothermal expansion is the area surrounding the tap spouts 18 and 20. Thisarea may extend from the top to a lower portion of the furnace, and toan arcuate distance covering maybe 120 measured 60 degrees on each sideof the tap spouts l8 and 20. The dimensions of the area are governed bythe lines of radiation from the hot metal ladle into which the vessel isbeing tapped, and are not restricted to any absolute values such asthose mentioned above. The distortion in the area around the tap spouts18 and 20 is resisted by providing a metal shell section lla (See FIG.2) having a thickness greater than that of the remainder of the shell.The thickness of the portion 1 1 a may be chosen as desired taking intoconsideration the overall design of the furnace 10. The thickness shouldnot be so great as to reduce the volume of the furnace. Most often thethickness of portion 1 1a will be selected on the basis of standardplate size. For example if standard 2 inch plate is used in fabricatingmetal shell 11, standard 6 inch plate might be used for portion 1 la.

The external areas of the vessel surrounding the tap spouts 18 and 20are exposed to the radiation of the molten metal as it is poured fromthe spouts into a ladle. The radiation also causes higher expansion tothe metal shell 11 in the area of the tap spouts 18 and 20 as comparedwith the rest of the shell. In order to reduce the distortion effectfrom the molten metal radiation, 1 provide heat shields covering thearea around the tap spouts 20. As shown, each heat shield 110 has alower portion 110a shaped generally in the form of a section of acylinder and an upper portion 110b shaped generally in the form of asection of a truncated cone. Together the lower and upper portions 110aand 1l0b cover an area of the furnace. A preferred area of each heatshield would be slightly more than the mouth area of the ladle intowhich the metal will be poured. Thus, if a shield 110 were laid on topof the ladle, it would completely cover the mouth of the ladle. Upperportion 1 10b has an opening cut therethrough to fit around tap spout 18or 20. A pair of clevis connections 114 located at the lower end of eachheat shield 110 serve to pivotally mount each heat shield to the metalshell 11 of the furnace 10. A pair of wedge type locks 116 fixed betweenthe top ends of each heat shield 110 locks the heat shields to thefurnace. The heat shields 110 thus act as heat sinks for the heat ofradiation emitted from the molten metal as it is being poured into aladle and thereby decreases the thermal expansion of the metal shield 11compared with expansion of the shell caused by direct radiation from themolten metal to the shell. The heat shields 1 10 may be pivoted into ahorizontal position in which case they may be used as work platforms.

Since this invention eliminates the need for a heavy trunnion ringimprovements such as the thickened shell and the heat shields may bemade to the furnace without concern for adding too much weight to thesupports. Other improvements could also be made, as for example,attaching stiffeners to the outer periphery of the furnace to reinforcethe metal shell against thermal expansion. The stiffeners would alsofunction as heat transfer radiating surfaces and would add to decreasingthe temperature of the metal shell. Even without stiffeners the metalshell of the furnace would tend to be cooler since elimination of thetrunnion ring exposes more heat transfer surface of the shell to theatmosphere.

It should be readily apparent that connecting and disconnecting thetrunnion shafts 21 and 50 to the furnace is simplified by the virtue ofthe arrangement of elements as described. Each trunnion shaft and itsbearing supports may be connected and disconnected as a unit from thefurnace. This permits the trunnion shafts and bearing supports to beassembled or disassembled in a shop away from the furnace.

While I have shown and described various embodiments of my presentinvention it should be clear that various changes and modifications maybe made in this invention within the contemplation of the followingclaims. Examples of such changes and modification have already beennoted hereinbefore. Also, there are various other advantages to theflexible connection support arrangement of my invention over trunnionring and direct shaft connection arrangements, as those skilled in theart could readily see.

lclaim:

1. In combination with a metal converting firnace, a pair of opposedsupport assemblies, each of which comprises:

ground supported shaft means coupled directly to an external portion ofthe furnace shell for supporting the furnace above ground level;

first and second connection means on said shaft means and the furnaceshell, respectively, and flexibly engaging each other for supporting thefurnace on said shaft means; and

one of said connection means having multiple external splines definedthereon, and the other of said connection means having multiple internalsplines defined therein, said splines mating with each other and beingshaped and sized with clearances to permit a certain degree ofmisalignment therebetween.

2. The combination as set forth in claim 1 wherein a clearance space isprovided between the free ends of the external splines and the ends ofthe internal splines.

3. The combination as set forth in claim 1 wherein said first connectionmeans includes the external splines and said second connection meansincludes the internal splines.

4. The combination as set forth in claim 3 including stop membersdisposed in the internal splines adjacent the free ends of the externalsplines. v

5. The combination as set forth in claim 1 including separate means forselectively securing said first and second connection means inengagement with each other.

6. The combination as set forth in claim 1 wherein said secondconnection means includes four similarly shaped brackets mounted on thewall of the furnace and arranged thereon to define a central pocket andfour slots generally 90 apart extending radially from the pocket; andsaid first connection means having a hub shaped and sized to fit withinsaid pocket and four lugs generally ninety degrees apart and shaped andsized to be received in said slots, with said slots and lugs beingshaped and sized to permit a certain degree of misalignmenttherebetween.

7. The combination as set forth in claim 6 including wear plate membersarranged in abutting relationship between the sides of said lugs andsaid slots.

8. The combination as set forth in claim 6 including retaining platesmounted on the wall of the furnace within the confines of said slots andarranged adjacent the free ends of said lugs.

9. The combination as set forth in claim 1 wherein said shaft means ofeach of the support assemblies is supported for rotation about agenerally horizontal axis with one of said shaft means being an idlershaft and arranged in bearing supports for limited movement along thehorizontal axis thereof toward and away from the furnace, and the otherof said shaft means being a driven shaft; and including power meansengageable with said driven shaft for driving same about the axis ofrotation thereof.

10. In combination with an open-mouth metal converting furnace, a pairof opposed support assemblies, each of which comprises:

ground supported shaft means with one end thereof being disposedadjacent an outer wall portion of the furnace and coupled to the furnacefor supporting the furnace above ground level;

a plurality of bracket members fixed to the wall of the furnace andarranged thereon in spaced relationship with each other to define aplurality of slots;

said shaft means having lugs thereon received in and engaging the wallsof said slots; and

said slots and lugs being shape-d and sized to permit certain degree ofmisalignment therebetween whereby the bracket members and said lugsserve as a flexible connection between the furnace and the shaft means.

l l. The combination as set forth in claim 10 wherein each supportassembly includes four bracket members fixed to the wall of the furnaceand arranged thereon to define four slots generally apart; and saidshaft means has four lugs generally 90 apart.

12. The combination as set forth in claim 10 wherein each supportassembly includes four bracket members fixed to the wall of the furnaceand arranged thereon to define a central pocket and four slots generally90 apart extending radially from the pocket; and said shaft means has ahub shaped and sized to fit within said pocket and four lugs generally90 apart.

13. The combination as set forth in claim 10 wherein when the furnace isin the metal charge position the centerline of one pair of diametricallyopposed slots and lugs lie in a generally vertical plane and thecenterline of the other pair of diametrically opposed slots and lugslies in a generally horizontal plane.

14. The combination as set forth in claim 10 wherein the shaft means ofboth support assemblies are supported for rotation about a commongenerally horizon tal axis, with one of said shaft means being an idlershaft and arranged in bearing supports for limited movement along thehorizontal axis thereof toward and away from the furnace, and the otherof said shaft means being a driven shaft; and including power meansengageable with said driven shaft for driving same about the axis ofrotation thereof.

15. The combination as set forth in claim 10 including a stop meansdetachably mounted on the furnace for engaging at least one of said lugsto secure said lugs in engagement with the walls of said slots.

16. In combination with an open-mouth metal con verting furnace, a pairof opposed support assemblies, each of which comprises:

ground supported shaft means with one end thereof being disposedadjacent an outer wall portion of the furnace and coupled to the furnacefor supporting the furnace above ground level;

a plurality of bracket members fixed to the wall of the furnace, each ofsaid bracket members having a lug thereon extending in the direction ofsaid shaft means;

said shaft means having a plurality of slots formed therein at said oneend portion thereof, each of said slots being shaped and sized toreceive one of said lugs; and

said slots and lugs being shaped and sized to permit a certain degree ofmisalignment therebetween, whereby the bracket members and said one endof said shaft means serve as a flexible connection between the furnaceand the shaft means.

17. The combination as set forth in claim 16 including stop meansdetachably mounted on the furnace for engaging said one end portion ofsaid shaft means to secure said lugs in engagement with said slots.

18. The combination as set forth in claim 16 wherein each of saidsupport assemblies includes four bracket members fixed to the wall ofthe furnace with the lugs thereof being generally in a circular patternabout 90 apart; and said shaft means has four slots generally 90 apart.

19. The combination as set forth in claim 16 wherein the shaft means ofboth support assemblies are supported for rotation, about a commongenerally horizontal, with one of said shaft means being an idler shaftand arranged in bearing supports for limited movement along thehorizontal axis thereof toward and away from the furnace, and the otherof said shaft means being a driven shaft; and including power meansengageable with said driven shaft for driving same about the axis ofrotation thereof.

20. The combination as set forth in claim 1 wherein said shaft means areground supported such that the longitudinal axes thereof arehorizontally fixed when the shaft means are disconnected from thefurnace.

21. The combination as set forth in claim wherein said shaft means areground supported such that the longitudinal axes thereof arehorizontally fixed when the shaft means are disconnected from thefurnace.

22. The combination as set forth in claim 16 wherein said shaft meansare ground supported such that the longitudinal axes thereof arehorizontally fixed when the shaft means are disconnected from thefurnace.

23. The combination as set forth in claim 1 wherein said first andsecond connection means are so constructed and arranged that the furnaceportion thereof will expand with the furnace during thermal expansionand away from said shaft means whereby overstressing between theengaging parts of the first and second connection means is avoidedduring thermal expansion of the furnace.

24. The combination as set forth in claim 1 wherein the furnace includesat least one metal tap spout; and including a heat shield plate membersupported by the furnace and spaced radially outwardly therefrom; saidplate member being shaped and sized to surround said tap spout and tocover a surface area of the furnace extending from the tap spoutcircumferentially away from both sides thereof and from an upper portionof the furnace to a lower portion thereof.

25. The combination as set forth in claim 1 wherein the furnace includesat least one metal tap spout; and wherein the metal shell of the portionhas a thickened portion in the area of said tap spout with saidthickened portion extending circumferentially away from both sides ofthe tap spout and from an upper portion to a lower portion of thefurnace.

1. In combination with a metal converting firnace, a pair of opposedsupport assemblies, each of which comprises: ground supported shaftmeans coupled directly to an external portion of the furnace shell forsupporting the furnace above ground level; first and second connectionmeans on said shaft means and the furnace shell, respectively, andflexibly engaging each other for supporting the furnace on said shaftmeans; and one of said connection means having multiple external splinesdefined thereon, and the other of said connection means having multipleinternal splines defined therein, said splines mating with each otherand being shaped and sized with clearances to permit a certain degree ofmisalignment therebetween.
 2. The combination as set forth in claim 1wherein a clearance space is provided between the free ends of theexternal splines and the ends of the internal splines.
 3. Thecombination as set forth in claim 1 wherein said first connection meansincludes the external splines and said second connection means includesthe internal splines.
 4. The combination as set forth in claim 3including stop members disposed in the internal splines adjacent thefree ends of the external splines.
 5. The combination as set forth inclaim 1 including separate means for selectively securing said first andsecond connection means in engagement with each other.
 6. Thecombination as set forth in claim 1 wherein said second connection meansincludes four similarly shaped brackets mounted on the wall of thefurnace and arranged thereon to define a central pocket and four slotsgenerally 90* apart extending radially from the pocket; and said firstconnection means having a hub shaped and sized to fit within said pocketand four lugs generally ninety degrees apart and shaped and sized to bereceived in said slots, with said slots and lugs being shaped and sizedto permit a certain degree of misalignment therebetween.
 7. Thecombination as set forth in claim 6 including wear plate membersarranged in abutting relationship between the sides of said lugs andsaid slots.
 8. The combination as set forth in claim 6 includingretaining plates mounted on the wall of the furnace within the confinesof said slots and arranged adjacent the free ends of said lugs.
 9. Thecombination as set forth in claim 1 wherein said shaft means of each ofthe support assemblies is supported for rotation about a generallyhorizontal axis with one of said shaft means being an idler shaft andarranged in bearing supports for limited movement along the horizontalaxis thereof toward and away from the furnace, and the other of saidshaft means being a driven shaft; and including power means engageablewith said driven shaft for driving same about the axis of rotationthereof.
 10. In combination with An open-mouth metal converting furnace,a pair of opposed support assemblies, each of which comprises: groundsupported shaft means with one end thereof being disposed adjacent anouter wall portion of the furnace and coupled to the furnace forsupporting the furnace above ground level; a plurality of bracketmembers fixed to the wall of the furnace and arranged thereon in spacedrelationship with each other to define a plurality of slots; said shaftmeans having lugs thereon received in and engaging the walls of saidslots; and said slots and lugs being shaped and sized to permit certaindegree of misalignment therebetween whereby the bracket members and saidlugs serve as a flexible connection between the furnace and the shaftmeans.
 11. The combination as set forth in claim 10 wherein each supportassembly includes four bracket members fixed to the wall of the furnaceand arranged thereon to define four slots generally 90* apart; and saidshaft means has four lugs generally 90* apart.
 12. The combination asset forth in claim 10 wherein each support assembly includes fourbracket members fixed to the wall of the furnace and arranged thereon todefine a central pocket and four slots generally 90* apart extendingradially from the pocket; and said shaft means has a hub shaped andsized to fit within said pocket and four lugs generally 90* apart. 13.The combination as set forth in claim 10 wherein when the furnace is inthe metal charge position the centerline of one pair of diametricallyopposed slots and lugs lie in a generally vertical plane and thecenterline of the other pair of diametrically opposed slots and lugslies in a generally horizontal plane.
 14. The combination as set forthin claim 10 wherein the shaft means of both support assemblies aresupported for rotation about a common generally horizontal axis, withone of said shaft means being an idler shaft and arranged in bearingsupports for limited movement along the horizontal axis thereof towardand away from the furnace, and the other of said shaft means being adriven shaft; and including power means engageable with said drivenshaft for driving same about the axis of rotation thereof.
 15. Thecombination as set forth in claim 10 including a stop means detachablymounted on the furnace for engaging at least one of said lugs to securesaid lugs in engagement with the walls of said slots.
 16. In combinationwith an open-mouth metal converting furnace, a pair of opposed supportassemblies, each of which comprises: ground supported shaft means withone end thereof being disposed adjacent an outer wall portion of thefurnace and coupled to the furnace for supporting the furnace aboveground level; a plurality of bracket members fixed to the wall of thefurnace, each of said bracket members having a lug thereon extending inthe direction of said shaft means; said shaft means having a pluralityof slots formed therein at said one end portion thereof, each of saidslots being shaped and sized to receive one of said lugs; and said slotsand lugs being shaped and sized to permit a certain degree ofmisalignment therebetween, whereby the bracket members and said one endof said shaft means serve as a flexible connection between the furnaceand the shaft means.
 17. The combination as set forth in claim 16including stop means detachably mounted on the furnace for engaging saidone end portion of said shaft means to secure said lugs in engagementwith said slots.
 18. The combination as set forth in claim 16 whereineach of said support assemblies includes four bracket members fixed tothe wall of the furnace with the lugs thereof being generally in acircular pattern about 90* apart; and said shaft means has four slotsgenerally 90* apart.
 19. The combination as set forth in claim 16wherein the shaft means of both support assemblies are supported forrotation, about a common generally horizontaL, with one of said shaftmeans being an idler shaft and arranged in bearing supports for limitedmovement along the horizontal axis thereof toward and away from thefurnace, and the other of said shaft means being a driven shaft; andincluding power means engageable with said driven shaft for driving sameabout the axis of rotation thereof.
 20. The combination as set forth inclaim 1 wherein said shaft means are ground supported such that thelongitudinal axes thereof are horizontally fixed when the shaft meansare disconnected from the furnace.
 21. The combination as set forth inclaim 10 wherein said shaft means are ground supported such that thelongitudinal axes thereof are horizontally fixed when the shaft meansare disconnected from the furnace.
 22. The combination as set forth inclaim 16 wherein said shaft means are ground supported such that thelongitudinal axes thereof are horizontally fixed when the shaft meansare disconnected from the furnace.
 23. The combination as set forth inclaim 1 wherein said first and second connection means are soconstructed and arranged that the furnace portion thereof will expandwith the furnace during thermal expansion and away from said shaft meanswhereby overstressing between the engaging parts of the first and secondconnection means is avoided during thermal expansion of the furnace. 24.The combination as set forth in claim 1 wherein the furnace includes atleast one metal tap spout; and including a heat shield plate membersupported by the furnace and spaced radially outwardly therefrom; saidplate member being shaped and sized to surround said tap spout and tocover a surface area of the furnace extending from the tap spoutcircumferentially away from both sides thereof and from an upper portionof the furnace to a lower portion thereof.
 25. The combination as setforth in claim 1 wherein the furnace includes at least one metal tapspout; and wherein the metal shell of the portion has a thickenedportion in the area of said tap spout with said thickened portionextending circumferentially away from both sides of the tap spout andfrom an upper portion to a lower portion of the furnace.